[builtins] Provide Math.floor as TurboFan builtin.

src/code-stubs.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/code-stubs.h"
 
 #include <sstream>
 
 #include "src/bootstrapper.h"
 #include "src/code-factory.h"
@@ skipping 841 matching lines @@
         }
       }
     }
   }
 
   assembler->Bind(&do_fadd);
   {
     Node* lhs_value = var_fadd_lhs.value();
     Node* rhs_value = var_fadd_rhs.value();
     Node* value = assembler->Float64Add(lhs_value, rhs_value);
-    // TODO(bmeurer): Introduce a ChangeFloat64ToTagged.
-    Node* result = assembler->AllocateHeapNumberWithValue(value);
+    Node* result = assembler->ChangeFloat64ToTagged(value);
     assembler->Return(result);
   }
 }
 
 void SubtractStub::GenerateAssembly(
     compiler::CodeStubAssembler* assembler) const {
   typedef compiler::CodeStubAssembler::Label Label;
   typedef compiler::Node Node;
   typedef compiler::CodeStubAssembler::Variable Variable;
 
@@ skipping 146 matching lines @@
         assembler->Goto(&loop);
       }
     }
   }
 
   assembler->Bind(&do_fsub);
   {
     Node* lhs_value = var_fsub_lhs.value();
     Node* rhs_value = var_fsub_rhs.value();
     Node* value = assembler->Float64Sub(lhs_value, rhs_value);
-    // TODO(bmeurer): Introduce a ChangeFloat64ToTagged.
-    Node* result = assembler->AllocateHeapNumberWithValue(value);
+    Node* result = assembler->ChangeFloat64ToTagged(value);
     assembler->Return(result);
   }
 }
 
 void BitwiseAndStub::GenerateAssembly(
     compiler::CodeStubAssembler* assembler) const {
   using compiler::Node;
 
   Node* lhs = assembler->Parameter(0);
   Node* rhs = assembler->Parameter(1);
@@ skipping 2335 matching lines @@
   if (type->Is(Type::UntaggedPointer())) {
     return Representation::External();
   }
 
   DCHECK(!type->Is(Type::Untagged()));
   return Representation::Tagged();
 }
 
 }  // namespace internal
 }  // namespace v8